A. Field of the Invention
The present invention relates to a system and method for the simultaneous display and manipulation of hierarchical and non-hierarchical data.
B. Description of the Prior Art
Traditional displays of linked objects are provided using tree-controlled layouts. These tree-controlled layouts, such as those provided in a list of files stored on a hard drive, include hierarchical information relating lower level hierarchical objects, such as files or programs, to higher level hierarchical objects, such as file folders or drive locations. An exemplary hierarchical structure could be a:\program files\program, wherein the hierarchy is as follows, on the “a” drive a folder entitled “program files” is stored, within which a program called “program” is stored. In this structure the “a” drive would be a higher level node linked to a lower level file folder node linked to a lower level file node.
For some computer storage structures both hierarchical and non-hierarchical links are provided between objects in the storage structures. Examples of computer storage structures including both hierarchical and non-hierarchical links are some computer file systems with links between files, hypertext systems, and the World Wide web. The use of non-hierarchical links is exemplified by web sites on the World Wide web, wherein hyperlinks may be provided within a current hypertext page of a Web site to create a link between the current hypertext page and a hypertext page that is not directly linked to the current document in the hierarchical structure of the Web site. These non-hierarchical links are not properly displayed in the traditional tree-control layout structures.
In a paper by Fairchild, K. M., Poltrock, S. E., and Furnas, G. W., entitled “SemNet: Three-Dimensional Graphic Representations of Large Knowledge Bases,” in Guindon, R., Ed., Cognitive Science and its Application for Human Computer Interaction, Lawrence Erlbaum, Hillsdale, N.J., 1988, pp. 201-33, SemNet, a three-dimensional graphical interface is described. SemNet presents views that allow users to examine local detail while maintaining a global representation of the rest of the knowledge base. SemNet also provides semantic navigation techniques such as relative movement, absolute movement, and teleportation.
U.S. Pat. No. 5,295,243 to Robertson et al., which is hereby expressly incorporated herein by reference, discloses a processor for presenting a sequence of images of a hierarchical structure that is perceived as a virtual three-dimensional structure. The hierarchical structure includes conic substructures that can have vertical or horizontal axes. Each conic substructures is presented having a parent node corresponding to its vertex and child nodes at the base of the conic substructure. The conic substructures may be rotated or rearranged by the user.